There are a number of situations in which aluminum metalization used for signal and power conductors in semiconductors devices must be applied to a platinum electrode. For example, ferroelectric capacitors for use in semiconductor devices typically comprise a ferroelectric material sandwiched between two electrodes. It is advantageous to use platinum for the electrodes. The signal connections in many semiconductor devices are constructed by depositing aluminum. However, aluminum cannot be deposited directly on platinum, as electrochemical reactions between the aluminum and the platinum will destroy the deposited aluminum layer.
One prior art solution to this problem utilizes a layer of titanium nitride to isolate the platinum from the aluminum. The titanium nitride is deposited by a sputtering technique that leads to deformities such as "bumps" in the titanium nitride layer. It is difficult to obtain a uniform aluminum layer in the presence of these deformities.
Broadly, it is the object of the present invention to provide an improved platinum-aluminum interconnect system.
It is a further object of the present invention to provide an improved platinum-aluminum interconnect system that provide a superior platinum binding surface for subsequent aluminum deposition.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.